How did Donald Davies contribute to the idea of packet switching?

Donald Davies was a British computer scientist who independently devised the concept of packet switching in the mid-1960s while working at the National Physical Laboratory (NPL) in the United Kingdom.12

His contributions to this technology include:

• Conceptualization: Davies developed a method to improve computer communication efficiency by breaking data streams into discrete, manageable blocks, which he termed "packets". These packets could be transmitted independently across a network and reassembled at their destination.1
• Terminology: He coined the term "packet switching," which was later adopted by Lawrence (Larry) Roberts for the ARPANET project after learning of Davies's work at a 1967 symposium.12
• Practical Implementation: Davies designed and built experimental networks at the NPL, specifically the Mark I (completed in 1970) and the Mark II (completed in 1973), to test and refine his theories.2

By creating a more flexible and efficient alternative to traditional circuit-switched networks, Davies’s work provided a foundational architecture for modern digital communications and the Internet.12